Anisotropic conductive film (ACF) has both unilateral conduction function and adhesion function. Currently, ACF is used for COG, TCP/COF, COB and FPC, in particular for the electric connection between IC and ITO glass. It can connect a lot of minuscule wires which traditional connectors can not connect.
Anisotropic conductive films are mainly applied to the products such as mobile handhelds, cell phones, digital cameras, computers, printers, keyboards, consumer electronics, TVs, GPS products, electronic dictionaries and so on.
Traditional ACF consists of thermosetting resin, conducting particles, curing agent, plasticizer and so on. When producing ACF, firstly, we dissolve the above-mentioned components in toluene, butanone or other volatile solvents to make a lot of anisotropic conductive adhesive (ACA). Secondly, we coat the above-mentioned ACA on a plastic film, then blow plenty of hot air to dry the ACA. Then the above-mentioned solvent is removed, and the ACF is produced. Then we cut the ACF to make up anisotropic conductive adhesive film (ACF). During the course of production, plenty of polluted harmful waste gas will affect the health of the workers.
The Chinese patent CN1926675A and the Chinese patent CN1367219A both disclose a kind of light curing anisotropic conductive adhesive (ACA) or light curing anisotropic conductive film (ACF). Those patents use light curing technology when using some ACF to connect some electric components. The ACA only can be used to connect transparent electrode (for example ITO glass), but can not be used to connect non-transparent electrode (for example plasma panel ADD etc). The Chinese patent CN 101724361 discloses the method about using heat curing to promote light curing, but it does not apply light curing technology to produce ACF. The adhesion strength of light curing is not as good as heat curing. In recent years, in micro-electronic packaging technology field, the connecting technology between those electronic components such as PCB terminals and IC chips develops to be integrated, high-performance, multi-lead, and of narrow space length. The requirements about the performance of the ACF is more and more high. Light curing can not meet the requirements about high bond strength.